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Overview ● Introductions ● Buoyancy as a platform for learning ● Hands on time ● An introduction to some tools for better measurement ● Code, hardware and getting data ● Fly, be free

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Buoyancy Any object, wholly or partially immersed in a fluid, is buoyed up by a force equal to the weight of the fluid displaced by the object. — Archimedes of SyracuseArchimedesSyracuse

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Let's check Archimedes against our measurements ● At 15 degrees Celsius air has a density of 1.225 Kg/m^3 at sea level ● If we measure the lifting power of our balloon what do we get? ● How do we measure? ● Archimedes says the volume displaced should be equivalent the buoyant force, what is the buoyant force and what is the volume?

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Where are the differences in our problem set? ● What does Helium weigh? ● Is the balloon fully filled? ● Is it spherical? ● What is the weight of the balloon? ● What is the weight of the string?

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Where are the differences in our problem set? ● What does Helium weigh? ● Is the balloon fully filled? ● Is it spherical? ● What is the weight of the balloon? ● What is the weight of the string? ● How would we get better numbers?

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What is Arduino? ● Hardware and Software ● Supports a range of hardware ● Free, open source, community supported ● Graphical environments ● Named after a bar

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Using some new tools ● Arduino Fio 8 bit microcontroller 32K of flash 8K of RAM This one includes a wireless footprint

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Using some new tools ● Arduino Fio 8 bit microcontroller 32K of flash 8K of RAM This one includes a wireless footprint

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Let's check the Serial Data ● Open the port and see that your data is flowing ● We'll click on the magnifying glass in the upper right corner ● We should see four values separated by commas

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Time to add wireless ● We need to plug the Xbee wireless units into the back of the Fio.Xbee ● Make sure the orientation matches the outline on the Fio board and be careful getting the pins lined up. If you aren't sure ask one of us ● We'll add the Xbee Explorer to the usb port and go to Arduino and look for a port to pull the data from.

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Time to fly ● Inflate, tether and fly at will! ● There are a number of options for logging and displaying the data ● The NSTA balloon code is comma seperated values and will load to Excel, Open Office and about any language that takes CSV ● For a nice terminal display, use the BMP 085 code

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More stuff ● Learn.sparkfun.com ● jeff.branson@sparkfun.com jeff.branson@sparkfun.com ● Included is the summer camp materials from the University of Colorado, Colorado Springs ● There are great balloon resources for the next level here; ● http://stilldavid.com/habfaq/